1. Field of the Disclosure
Embodiments of the present disclosure relate generally to power management and specifically to a system and method for controlling phase-to-phase imbalances and reducing the circulating current in a parallel modular converter system.
2. Background of Related Art
Modern vehicles use a large number of electronics, motors, heaters, and other electrically driven equipment. Electric motors, in particular, are ubiquitous in modern vehicles, including aircraft, and power everything from hydraulic pumps to cabin fans. Conventionally, each of these electric motors has been driven by an independent motor controller. Each motor controller is sized to be able to carry the maximum amount of current required to power its respective motor at full power for an extended period of time (and generally, includes some additional capacity for safety) without overheating or malfunctioning.
As a result, each aircraft carries an excessive number of motor controllers, each of which is oversized and underutilized a majority of the time. In other words, the motor controller includes enough capacity to run the motor at full power for an extended period of time plus a safety margin, but motors are rarely, if ever, run at full capacity. This is because the motors themselves have some safety margin built in and because, a majority of the time, the motors are operating in a lower demand regime (e.g., the cabin fan is not always on “High”). In addition, some motors are only used occasionally, or during specific flight segments, and are unused the remainder of the time. As a result, many of an aircraft's complement of heavy, expensive motor controllers spend a majority of their service life either inactive or significantly below their rated power outputs.
What is needed, therefore, is a system architecture that enables the use of multiple, modular, assignable, dynamically reconfigurable parallel motor controllers that can work alone or in parallel with other parallel motor controllers to meet power control needs. The system should enable one or more parallel controllers to be assigned to each active electrical load in the aircraft, as necessary, to meet existing power demands. The system should enable the use of such parallel controllers, while minimizing phase-to-phase imbalances and reducing circulating current. It is to such a system that embodiments of the present disclosure are primarily directed.